As an image forming device for a printer, a facsimile, a reproducing unit, a plotter, and a multifunctional unit having these functions, an inkjet recording device is known as a liquid discharge recording-type image forming device using a recording head which discharges an ink droplet, for example.
The liquid discharging recording-type image forming device discharges the ink droplet from the recording head to a sheet to be conveyed (not limited to paper and includes an OHP sheet, representing what the ink droplet and other liquid, etc., can be adhered to; also called a medium to be recorded on, or a recording medium, recording paper, a recording sheet) to perform image forming (recording, print, imaging, printing also used interchangeably). The liquid discharging recording-type image forming device includes a serial-type image forming device which discharges a liquid droplet while the recording head moves in a main scanning direction and a line-type image forming device with the use of a line-type head which discharges an droplet while the recording head does not move to perform image forming.
Herein, a liquid discharging-type “image forming device” represents a device which discharges a droplet to a medium such as paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, etc., while “image forming” represents not only providing a medium with an image which has a meaning (e.g., character or graphics), but also providing a medium with an image which does not have a meaning (merely causing a droplet to impact the medium, i.e., a liquid discharging device). Moreover, “ink” is not limited to what is called ink, but all types of liquids which can perform image forming, such as what is called recording liquid, fixing solution, liquid, etc., and includes DNA sample, resist, pattern material, resin, etc., for example.
An image forming device (below called merely “inkjet-type recording device”) is known, wherein a sub-tank (also called a buffer tank or a head tank) is mounted on a carriage which has mounted thereto a recording head to which ink is supplied from the sub-tank, a main ink cartridge (also called a main tank) is removably mounted on the side of the image forming device body (merely called “device body” below), and ink is replenished to the sub-tank from the main ink cartridge on the side of the image forming device body.
For example, an ink cartridge is known which tucks into a divided cartridge housing an ink containing bag having the body thereof fixed by welding, etc., to a holding member having an ink supply port section and an ink filling port section and which has the holding member held by a holding unit of the cartridge housing (Patent documents 1 and 2). Moreover, an ink cartridge is also known which includes a casing provided with an opening section at a lower portion of an inner front face and a bag which is collapsible into a sheet-like configuration, a front edge of which bag being connected to a spout fixed to the opening section (Patent document 3).
Moreover, an ink cartridge is known which is structured to directly weld or adhere, to a flexible bag shaped body which stores ink, a rubber-like body into which an aspiration needle may be inserted (Patent document 4).
Moreover, an ink carrying container is disclosed, which is formed of a flexible material, which is held by fixing a supply section within a hard casing, and which is formed by direct blow molding, wherein, in order to reduce the remaining amount of ink, an efficiently collapsible supporting fold is molded with a line-shaped projection section which is formed on an inner face of a metal mold for blow molding (Patent document 5).    Patent document 1: JP3919734    Patent Document 2: JP2004-276538    Patent Document 3: JP2004-034696    Patent document 4: Japanese utility model application publication No. 02-144438    Patent document 5: JP2005-059482
However, as described above, there is a problem that, with an ink cartridge which uses an ink bag whose body has, fixed thereto by welding, etc., a holding member having a supply port section, the number of parts becomes large and that, at the time of welding the holding member and the bag body, etc., dust is likely to find its way therebetween. There is a similar problem with an ink cartridge with the front edge of a bag thereof being connected to a spout.
Moreover, with a structure having a rubber-like body directly welded or adhered to an ink containing section, there is a problem that it is not easy to have the rubber-like body directly welded or adhered when the ink containing section is made of resin with low adherence, so that the durability of the portion in question is not sufficient.